Three-circuit heat exchanger



FIG. 1 is a top plan view of showing my design thereof;

FIG. 2 is a bottom plan view;

FIG. 3 is a right side elevation view;

FIG. 4 is a left side elevation view;

FIG. 5 is a first end elevation view;

FIG. 6 is a second end elevation view;

FIG. 7 is a front perspective view; and,

FIG. 8 is a rear perspective view of thereof. 

The ornamental design for three-circuit heat exchanger, as shown and described. 